Slow "For" Loop to reduce loading times

My game randomly generates the next level as you advance onto the next level. This works perfectly, but every time it loads a level, it lags for a frame or two while it loads. What im doing is generating teh levels using a “For” loop. Instead i would like to load the levels by generating each ramp, one after the other instead of at the same time. Here’s an old example of my game: http://fpsyndicate.webs.com/ramprunner.htm

So i want to load each ramp on the new level the next frame, one after another to prevent this little glitch. (You may not be able to see it, but it happens on slow computers and mobile phones.)

Do that inside a coroutine and use yield null (unityscript) or yield return null (c#) to wait one frame.